1. Field of the Invention
The present invention relates to a faulty weft yarn removing apparatus capable of removing a faulty weft yarn smoothly when a picked weft yarn is broken in the fabric so that a so-called broken pick occurs.
2. Description of the Related Art
In a shuttleless loom such as an air jet loom and a water jet loom, a faulty weft yarn removing device is often used to extract the faulty weft yarn from the fabric and perform automatic restart of the loom when a mispick (which refers to a weft yarn which causes a faulty picking phenomenon such as short pick, long pick, bent pick, broken pick by the jet of picking fluid or some other causes, etc.) occurs.
The faulty weft yarn removing apparatus may remove the faulty weft yarn from the receiving side as well as the picking side of the fabric by disposing weft yarn extracting devices on the picking side and the receiving side of the fabric, respectively, so that the apparatus may cope with the mispick even when a picked weft yarn is cut off and broken pick occurs in the fabric (for example, U.S. Pat. No. 4,730,643).
The faulty weft yarn removing apparatus as described above is provided with a first weft yarn feeler which detects a correctly picked weft yarn and a second weft yarn feeler disposed downstream in the picking direction, on the receiving side of the fabric. When the second weft yarn feeler detects the weft yarn, the apparatus determines whether the mispick is long pick or broken pick by simultaneously referring to a measuring signal transmitted from an unwinding detector. Namely, when the measuring signal indicates an error, the faulty weft yarn removing apparatus determines that the mispick is long pick and actuates only the weft yarn extracting device on the picking side in order to remove the faulty weft yarn from the picking side in the direction opposite to the picking direction. When the measuring signal is normal, the faulty weft yarn removing apparatus determines that the mispick is a broken pick and actuates both of the weft yarn extracting devices In order to remove the faulty weft yarn in both directions.
According to the prior art, when long pick and broken pick concur, the weft yarn extracting device disposed on the receiving side is not actuated and the broken end of the faulty weft yarn is not removed. The reason is that because the measuring signal indicates an error, only the weft yarn extracting device on the picking side is actuated to cope with long pick. If the weft yarn extracting device disposed on the receiving side is arranged to be also actuated unconditionally at the same time as the weft yarn extracting device on the picking side, both of the weft yarn extracting devices extract the faulty weft yarn from both sides upon the occurrence of simple long pick without broken pick so that the faulty weft yarn is cut off, and the cut end is sprung back and twisted around wrap yarns. Thus it is extremely difficult to remove the faulty weft yarn. On the other hand, if the apparatus is arranged so as to be able to detect the occurrence of a broken pick in order to avoid such a problem, it is necessary to arrange another special detector in the loom. However, such an arrangement is difficult to realize.